Linen washing sewage is mostly the hotel washing clothes or bed linen waste water, which co
ntains detergent and sand hair and other particles, it is relatively simple to meet the discharge standards. But now the water discharge requirements are more and more strict, so the EIA requirements of many washing plants are reuse, that is, zero discharge or less discharge. Then the problem also appears, the soluble substances co
ntained in sewage can not be solved by simple filtration and precipitation. Although the amount of soluble organic matter and inorganic salt in sewage is small, the water quality will become worse and worse and the hardness will become higher and higher after repeated use and accumulation.
Laundry wastewater includes washing wastewater, cleaning wastewater and dewatering wastewater. The water quality characteristics of each laundry wastewater:
1. The washing wastewater contains a lot of staple fiber and laundry detergent foam, which has a high COD value and is turbid;
2. Large amount of cleaning wastewater, a small amount of foam, less suspended matter, small COD value, more transparent;
3. The amount of dewatering wastewater is small, and the water quality is slightly better than that of cleaning wastewater.